When looking at liquid measurements in medicine and science, the terms “cc” and “mL” are often used interchangeably. But are they actually the same unit of measurement? The quick answer is yes, 2cc is equivalent to 2 mL. However, understanding the background behind these units provides more insight.

## What is a cc?

Cc stands for cubic centimeter. A cubic centimeter is a unit of volume equal to one milliliter (1 mL). The cc abbreviation comes from the French word “centimes cubes” meaning cubed centimeter.

One cc represents a volume of 1 cm x 1 cm x 1 cm. Given that 1 cm cubed equals 1 mL, 1 cc is therefore equivalent to 1 mL. The cc unit was commonly used in medicine and science but has been replaced by mL in most settings.

## What is a mL?

mL stands for milliliter. A milliliter is defined as 1/1000 of a liter. Given that a liter is a cube with sides of 10 cm, 1 mL is 1/1000 of a 10 cm x 10 cm x 10 cm cube. When calculated, this also works out to be 1 cm x 1 cm x 1 cm – the same as 1 cc.

So 1 mL represents the same volume as 1 cc. The mL abbreviation is from the French word “millilitre” meaning one-thousandth of a liter. The mL unit was introduced along with other metric measurements and is now the standard unit used for liquid volumes in medicine, pharmacy, and science.

## The Metric System

The cc and mL units both originated in the development of the metric system in France. The metric system was created to establish a universal system of weights and measures (as opposed to the varying regional or national systems). It is based on decimal units and two main units – the meter (for length) and the gram (for mass).

The liter was defined as a unit of volume based on the meter. A liter is equal to 1000 cubic centimeters. The liter allowed for standardized measurement of liquid volumes across science and medicine. The cc and mL units were derived from the liter to provide smaller units of fluid measure.

## Metric Volume Units

The cc and mL are part of a standardized set of metric volume units based on powers of 10. For example:

- 1 mL = 1 cubic centimeter = 0.001 L
- 1 L = 1000 mL = 1000 cc
- 1 dL (deciliter) = 100 mL
- 10 mL = 1 cl (centiliter)

Having interrelated metric units allows fluid volumes to be easily converted from larger to smaller units and vice versa, using multiples of 10.

## The Transition from cc to mL

The cc unit was an early cubic centimeter unit proposed by French scientists developing the metric system in the late 1700s. It became widely used in the medical field alongside other cgs (centimeter-gram-second) units. However, in 1960, the cc was officially replaced by the alternative mL unit in the international system of units (SI).

The transition was primarily driven by the need to harmonize different cubic centimeter notation variants that had arisen. Having a standardized abbreviation (mL) avoided confusion from the use of cc, ccm, cm3, and other versions. The mL gained broader international acceptance and was adopted by medical regulatory bodies like the FDA in the United States.

While some scientific documents may still use cc, today mL is recognized as the official SI unit for liquid volume. Any use of cc is understood to be interchangeable with mL.

## Does the difference matter?

In most practical contexts, cc and mL can be used interchangeably. Since 1 cc equals 1 mL, converting between them is simple. For example:

- 2 cc = 2 mL
- 5 cc = 5 mL
- 0.5 cc = 0.5 mL
- 10 cc = 10 mL

Whether a volume is labeled as 2 cc or 2 mL, the actual volume remains the same. So in every day applications, the terms can generally be used synonymously without affecting the meaning.

However, within formal scientific literature or medical documentation, mL is considered the more appropriate term. Using the accepted SI unit helps maintain consistency and avoid ambiguity in written works. For formal writing, mL is recommended over cc.

The difference also matters when reporting doses of medication. For safety, medical professionals should only use mL to prevent any misinterpretation of unlabeled cc abbreviations. Clear communication helps avoid medication errors.

## Advantages of mL over cc

Given its formal adoption into the SI system and more widespread use, mL has several advantages over cc:

- mL is the internationally recognized standard abbreviation.
- mL avoids confusion with other ccm, cm3 versions.
- mL is consistent with other metric volume units.
- mL is the accepted terminology in medical settings.

Essentially, mL is clearer, more consistent, and less prone to misunderstanding compared to cc. Although the volumes are equal, the mL unit provides uniformity. Using mL over cc ensures standardization as volume measurements are communicated or converted.

## mL usage in medicine

In medicine, mL is used to measure:

- Liquid medications – e.g. 1 mL of ibuprofen syrup
- Injections or intravenous (IV) fluids – e.g. 5 mL injection
- Urine output – e.g. 400 mL/day
- Drops (gtt) – 1 mL = 20 drops so 10 mL = 200 drops

The milliliter allows for precise quantification of fluids used in medical treatment. Dosages and IV infusion rates are all specified in mL per minute or per hour. This provides consistency and safety across healthcare settings.

## mL usage in science

In science, the milliliter is the unit of choice for:

- Preparing laboratory reagents
- Measuring liquids for experiments
- Titrating solutions during volumetric analysis
- Calibrations and quality control testing
- Reporting results of analyses

Once again, having standardized volume units is vital for maintaining accuracy and reproducibility in science. Although some older research may report volumes in cc, current scientific practice uses mL.

## mL equivalents

Since the milliliter is an SI volume unit, it can be converted into other standard volume measurements:

- 1 mL = 1 cc
- 1 mL = 0.0338 U.S. fluid ounces
- 1 mL = 0.06102 U.S. teaspoon
- 1 mL = 0.0351951 U.S. tablespoon

These equivalencies can help relate mL to everyday cooking measurements. However, for scientific accuracy, converting between metric volumes is recommended.

## Converting cc to mL

When needed, cc values can easily be converted to mL:

- 1 cc = 1 mL
- 10 cc = 10 mL
- 1.5 cc = 1.5 mL
- 0.1 cc = 0.1 mL

To convert, simply replace the cc with mL. So a 100 cc solution is equivalent to a 100 mL solution. This straightforward conversion allows cc directions to be followed using the standard mL unit.

## Converting mL to cc

Converting mL to the obsolete cc is not typical. But should this be required:

- 1 mL = 1 cc
- 10 mL = 10 cc
- 1.5 mL = 1.5 cc
- 0.1 mL = 0.1 cc

Again, the conversion is a direct replacement of mL with cc. So 100 mL is equal to 100 cc.

## Volume equivalents between units

Unit | Volume Equivalents |
---|---|

1 milliliter (mL) | 1 cc, 0.001 L, 0.0338 fl oz, 0.06102 tsp, 0.0351951 tbsp |

1 cubic centimeter (cc) | 1 mL, 0.001 L, 0.0338 fl oz, 0.06102 tsp, 0.0351951 tbsp |

1 liter (L) | 1000 mL, 1000 cc, 33.814 fl oz, 202.884 tsp, 67.628 tbsp |

## Converting between units

### mL to/from Liters

- mL to liters: divide mL by 1000
- Liters to mL: multiply liters by 1000

Examples:

- 500 mL = 0.5 L
- 1.5 L = 1500 mL

### mL to/from cc

- mL to cc: no conversion needed, amounts are equal
- cc to mL: no conversion needed, amounts are equal

Examples:

- 10 mL = 10 cc
- 0.2 cc = 0.2 mL

### mL to fluid ounces

- mL to fl oz: multiply mL by 0.0338
- Fl oz to mL: divide fl oz by 0.0338

Examples:

- 100 mL x 0.0338 = 3.38 fl oz
- 2 fl oz / 0.0338 = 59.1 mL

## Practical examples

### Medical examples

A patient is prescribed 25 mL of ibuprofen syrup every 6 hours. This is the same as 25 cc of ibuprofen syrup every 6 hours.

An IV infusion is running at 125 mL/hour. This infusion rate could also be stated as 125 cc/hour.

A 2 liter saline IV bag contains 2000 mL or 2000 cc of fluid.

### Laboratory examples

A chemistry experiment calls for 100 mL of 1 M hydrochloric acid solution. This could be measured out as 100 cc instead.

A microbiology media preparation directs adding 5 mL of growth supplements to 500 mL of agar broth. This is equivalent to adding 5 cc of supplements to 500 cc of agar.

A solvent extraction procedure specifies combining 50 mL of organic solvent with the sample. 50 cc of the organic solvent could also be used.

## Key Points

- The mL (milliliter) and cc (cubic centimeter) units represent the same volume measurement.
- 1 mL equals 1 cc – the units are interchangeable.
- Both units indicate a volume of 1 cm x 1 cm x 1 cm.
- The cc abbreviation is falling out of use – mL is now the standard SI unit.
- In formal writing, science, and medicine – mL is preferred over cc.
- mL helps avoid ambiguity and aids in uniformity and precision.
- Conversion between mL and cc is direct since the volumes are identical.

## Conclusion

In summary, 2cc is equivalent to 2mL – the volumes are the same. The cc and mL units originated from the metric system and both represented a cubic centimeter. While both were used historically, mL has been formally adopted as the SI unit and is the standard abbreviation. The use of mL over cc provides consistency and avoids confusion in science and medicine. Therefore, while the cc abbreviation still appears in some contexts, mL is the preferred, internationally recognized terminology.